scholarly journals Modelling the Influence of Manufacturing Process Variables on Dimensional Changes of Porcelain Tiles

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Dolly Santos-Barbosa ◽  
Dachamir Hotza ◽  
Juan Boix ◽  
Gustavo Mallol

A model to study the influence of main process variables (powder moisture, maximum compaction pressure, and maximum firing temperature) on the intermediate variables (mass, dry bulk density, size, and thickness) and the final dimensions of porcelain tiles is proposed. The properties of dried and fired bodies are basically determined by the process parameters when the physical, chemical, and mineralogical characteristics of the raw material are kept constant. For a given set of conditions, an equation could be sought for each property as a function of raw materials and processing. In order to find the relationship between moisture content and compaction pressure with dry bulk density, springback, and drying and firing shrinkage, a laboratory experimental design with three factors and four levels was applied. The methodology was validated in lab scale for a porcelain tile. The final size and thickness were estimated, and the influence of the main process variables was analysed.

2014 ◽  
Vol 92 ◽  
pp. 188-193 ◽  
Author(s):  
Tuna Aydin ◽  
Alpagut Kara

Spodumene, which is a lithium alumina silicate, has been used as a raw material in the production of thermal shock resistant whitewares and sanitarywares. The presence of spodumene results in enhancement of mullitization and imparts better physical and mechanical properties to ceramics. In this study, the influence of Lithium alumina silicate phases on the mechanical properties of standard porcelain stoneware body was investigated. Especially solid-solid reactions were observed between spodumene and quartz or spodumene and clay. These solid-solid reactions bring about a newly formed lithium alumina silicate (LAS) phases. Spodumene allows the development of a low viscosity liquid phase and results in a decrease in closed porosity, also with increase in bulk density, bending strength and elastic modulus.


Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 174 ◽  
Author(s):  
Peter Blistan ◽  
Stanislav Jacko ◽  
Ľudovít Kovanič ◽  
Julián Kondela ◽  
Katarína Pukanská ◽  
...  

A frequently recurring problem in the extraction of mineral resources (especially heterogeneous mineral resources) is the rapid operative determination of the extracted quantity of raw material in a surface quarry. This paper deals with testing and analyzing the possibility of using unconventional methods such as digital close-range photogrammetry and terrestrial laser scanning in the process of determining the bulk density of raw material under in situ conditions. A model example of a heterogeneous deposit is the perlite deposit Lehôtka pod Brehmi (Slovakia). Classical laboratory methods for determining bulk density were used to verify the results of the in situ method of bulk density determination. Two large-scale samples (probes) with an approximate volume of 7 m3 and 9 m3 were realized in situ. 6 point samples (LITH) were taken for laboratory determination. By terrestrial laser scanning (TLS) measurement from 2 scanning stations, point clouds with approximately 163,000/143,000 points were obtained for each probe. For Structure-from-Motion (SfM) photogrammetry, 49/55 images were acquired for both probes, with final point clouds containing approximately 155,000/141,000 points. Subsequently, the bulk densities of the bulk samples were determined by the calculation from in situ measurements by TLS and SfM photogrammetry. Comparison of results of the field in situ measurements (1841 kg∙m−3) and laboratory measurements (1756 kg∙m−3) showed only a 4.5% difference in results between the two methods for determining the density of heterogeneous raw materials, confirming the accuracy of the used in situ methods. For the determination of the loosening coefficient, the material from both large-scale samples was transferred on a horizontal surface. Their volumes were determined by TLS. The loosening coefficient for the raw material of 1.38 was calculated from the resulting values.


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1809 ◽  
Author(s):  
Marek Wróbel ◽  
Marcin Jewiarz ◽  
Krzysztof Mudryk ◽  
Adrian Knapczyk

For biomass compaction, it is important to determine all aspects of the process that will affect the quality of pellets and briquettes. The low bulk density of biomass leads to many problems in transportation and storage, necessitating the use of a compaction process to ensure a solid density of at least 1000 kg·m−3 and bulk density of at least 600 kg·m−3. These parameters should be achieved at a relatively low compaction pressure that can be achieved through the proper preparation of the raw material. As the compaction process includes a drying stage, the aim of this work is to determine the influence of the drying temperature of pine biomass in the range of 60–140 °C on the compaction process. To determine whether this effect is compensated by the moisture, compaction was carried out on the material in a dry state and on the materials with moisture contents of 5% and 10% and for compacting pressures in the 130.8–457.8 MPa range. It was shown that drying temperature affects the specific density and mechanical durability of the pellets obtained from the raw material in the dry state, while an increase in the moisture content of the raw material neutralizes this effect.


2017 ◽  
Vol 899 ◽  
pp. 576-580 ◽  
Author(s):  
Daniel Rodrigues ◽  
Gilberto Vicente Concílio ◽  
Jose Adilson de Castro ◽  
Marcos Flavio de Campos

Compression moulded NdFeB bonded magnets can advantageously replace the sintered version in applications that require specific shape and size. The maximum densities that can be obtained for ready-to-press commercial raw materials are close to 6.0 g/cm3. For large pieces, uniaxially pressed, densities should be limited to values as 5.0 g/cm3 due to the friction during compression. This paper investigate the effects of final density (ranging from 5.0 to 6.0 g/cm3) on the magnetic of compression moulded magnets. A ready-to-press Magnequench MQPB+ was used as raw material. Small cylindrical samples were produced by press and cure. Results are presented and discussed considering aspects related to relative densities. The magnetic properties are dependent of density, and coercivity decreases with deformation during compaction.


2019 ◽  
Vol 51 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Blasius Ngayakamo ◽  
Eugene Park

The present work has evaluated Kalalani vermiculite as a potential raw material for the production of high strength porcelain insulators. Three porcelain compositions were prepared to contain 0, 20 and 30 wt% of Kalalani vermiculite. Porcelain samples were fabricated using a semi-drying method. The chemical, mineralogical phases and microstructural characterization of the raw materials were carried out using XRF, XRD, and SEM techniques, respectively. Water absorption, bulk density, dielectric and bending strengths were performed on porcelain samples fired up to 1300?C. However, at the sintering temperature of 1250?C, the porcelain sample with 20 wt% of Kalalani vermiculite gave the dielectric strength of 61.3 kV/mm, bending strength of 30.54 MPa, bulk density of 2.21 g/cm3 and low water absorption value of 0.21 % which is the prerequisite properties for high strength porcelain insulators. It was therefore concluded that Kalalani vermiculite has the potential to be used for the production of high strength porcelain insulators


2013 ◽  
Vol 785-786 ◽  
pp. 1066-1071
Author(s):  
Jian Feng Wu ◽  
Bin Zheng Fang ◽  
Xiao Hong Xu ◽  
Xin Bin Lao

The cordierite was synthesized at relatively low temperature by pressureless sintering method, using calcined bauxite, talcum , quartz and feldspar as raw materials in this paper. The water absorption (Wa), porosity (Pa), bulk density (Db) and bending strength of samples have been tested, and the synthetic process and mechanism have been investigated by XRD, SEM, and so on. The results showed that the cordierite could be synthesized at 1280°C and the range of synthetic temperature is 1160~1300°C, when the sample was sintered at 1280°C for 2h, its bulk density and bending strength were 2.20g/cm3and 72.13MPa, respectively. XRD analysis showed that the main phase of sample was cordierite, the cordierite content was about 88wt%, and the minor phases were MgAl2O4spinel and corundum. SEM results showed that the samples were dense and the pore sizes were 5 μm~100μm, the grains were growth and development well, the grains size were 0.5μm~6μm. High reaction activity corundum and mullite were provided by calcined bauxite, then coupled with the role of feldspar, thus reduced the synthetic temperature of cordierite.


Cerâmica ◽  
2015 ◽  
Vol 61 (360) ◽  
pp. 442-449 ◽  
Author(s):  
Álvaro Guzmán A ◽  
Silvio Delvasto A ◽  
Maria Francisca Quereda V ◽  
Enrique Sánchez V

Abstract The rice industry generates huge amounts of rice straw ashes (RSA). This paper presents the results of an experimental research work about the incorporation of RSA waste as a new alternative raw material for production of porcelain tiles. The RSA replaces, partially or completely, the non-plastic raw materials (quartz (feldspathic sand in this research) and feldspar), that together with the clays, constitute the major constituents of formulations of porcelain tiles. A standard industrial composition (0% RSA) and two more compositions in which feldspar and feldspathic sand were replaced with two percentages of RSA (12.5% RSA and 60% RSA) were formulated, keeping the clay content constant. The mixtures were processed, reproducing industrial porcelain tile manufacturing conditions by the dry route and fired at peak temperatures varying from 1140-1260 ºC. The results showed that additions of 12.5% RSA in replacement of feldspar and feldspathic sand allowed producing porcelain tiles that did not display marked changes in processing behaviour, in addition to obtain a microstructure and the typical mineralogical phases of porcelain tile. Thus, an alternative use of an agricultural waste material is proposed, which can be translated into economic and environmental benefits.


2020 ◽  
Vol 24 (2) ◽  
pp. 55-63
Author(s):  
Sławomir Gawłowski ◽  
Ryszard Kulig ◽  
Grzegorz Łysiak ◽  
Al Aridhee Jawad Kadhim ◽  
Zdybel Adam ◽  
...  

AbstractThe objective of the paper was to determine the impact of moisture and rotational speed of threshers on the process of crushing of lupine seeds. Raw material was led to four levels of moisture from 8 to 14% every 2%. The studies were carried out on the laboratory hammer mill with the use of variable speeds of mill hammers within 5500-7000 rot∙min−1. The studies that were carried out proved significant relations (p<0.05) between the analysed process variables and energy consumption and susceptibility of seeds to crushing. It was stated that along with the increase of the rotational speed, a reduction in the drop of the average dimension of particles of mill takes place. Along with the increase of moisture of lupine from 8 to 14% a unit energy of crushing increases on average by approx. 83%. It was proved that the susceptibility ratio of seeds to crushing increases along with the increase of raw material moisture. Such relations were determined for all investigated rotational speeds of hammers.


2020 ◽  
Vol 17 (34) ◽  
pp. 678-688
Author(s):  
Maratbek T ZHUGINISSOV ◽  
Zhanar O ZHUMADILOVA

Ashes slag materials in the chemical and mineralogical composition are largely identical to natural mineral raw materials. They are a source of environmental pollution, pose a threat to public health, and a threat to the flora and fauna of the surrounding areas. Ashes slag waste contains a large amount of unburned fuel. In some ashes, the content of unburned fuel can reach 20-40%. In this case, it is advisable to use it as a raw material for the production of artificial porous aggregates. The paper presents the results of studies on the development of lightweight aggregate technology based on ashes slag with a high residual fuel content. To develop the technology of lightweight aggregate, ashes slag was used by Nova Zinc LLP (Karaganda region, Kazakhstan), in which the content of unburned coal is up to 75%. Based on ashes slag, lightweight aggregates were obtained using burning and non-burning technologies. By roasting (burning) technology, aggregates were obtained by burning at a temperature of 1000 and 1100 °C. The aggregates obtained have a bulk density of 395-687 kg/m3 and a compressive strength in the cylinder of 0.5-2.4 MPa. By non-burning technology Portland cement M400 was used as an astringent. After hardening, the aggregates have a bulk density of 400-600 kg/m3 and a 679 compressive strength of 0.65-1.5 MPa in the cylinder. Samples of light concrete with a density of 1200 and 1700 kg/m3, a compressive strength of 80 (B5) and 120 kg/cm2 (B7.5), and thermal conductivity coefficients of 0.43 and 0.67 W/mоС were obtained on the basis of the non-fired light aggregate, respectively. Lightweight aggregate and lightweight concrete in their functional properties meet the requirements of regulatory documents.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
D. Eliche-Quesada ◽  
M. A. Felipe-Sesé ◽  
A. Infantes-Molina

This work evaluates the effect of incorporation of olive stone ash, as secondary raw material, on the properties of fired clay bricks. To this end, three compositions containing 10, 20, and 30 wt% olive stone ash in a mixture of clays (30 wt% red, 30 wt% yellow, and 40 wt% black clay) from Spain were prepared. The raw materials, clay and olive stone ash, were characterized by means of XRD, XRF, SEM-EDS, and TG-TDA analysis. The engineering properties of the press molded specimens fired at 900°C (4 h) such as linear shrinkage, bulk density, apparent porosity, water absorption, and compressive strength were evaluated. The results indicated that the incorporation of 10 wt% of olive stone ash produced bricks with suitable technological properties, with values of compressive strength of 41.9 MPa but with a reduced bulk density, by almost 4%. By contrast, the incorporation of 20 wt% and 30 wt% sharply increased the water absorption as a consequence of the large amount of open porosity and low mechanical strength presented by these formulations, which do not meet the standards for their use as face bricks. The bricks do not present environmental problems according to the leaching test.


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